The invention relates to the discovery of the biologically active R-enantiomer of N-carbamoylmethyl-4-aryl-2-pyrrolidinone and easy and effective method of its preparation.
It is known that humans in a stress situation or under psycho-emotional strain exhibit irrational and inadequate forms of behavior, disorders of mental capacity, declined speed of reaction, and increased number of erroneous decisions etc.
Therefore discovery of pharmaceuticals abating and preventing the effect of a stress factor is of substantial importance. For this purpose the nootropic GABA derivatives: Phenibut and Baclofen are applied, even though their use is followed by drowsiness, depression, dizziness, lowered psychomotor reactions etc.
In comparison to GABA derivatives another agent widely used for this purpose N-carbamoylmethyl-4-aryl-2-pyrrolidinone (Carphedon, INN) could be regarded as a much more perspective psycho-stimulator due to the less pronounced side effects.
The R- and S-enantiomeric forms of Carphedon and their pharmacologic properties are not known. The pharmacologic properties of only the racemic Carphedon are published today and there is no data concerning possible differences of pharmacological properties for its separate R- and S-enantiomers. The absence of this highly important information also does not allow to adequately estimate the real pharmaceutical potential of Carphedon already used in medicine, because in reality it is represented by a mixture of R- and S-enantiomers, which may exhibit different pharmacologic properties.
In the present invention we have developed methods for preparation of pure R- and S-Carphedon and unexpectedly discovered that R-Carphedon as an antidepressant, analgesic, muscle relaxant and psycho-stimulating compound is more effective than the racemic Carphedon or S-Carphedon.